kilda



UNITED STATE PATENT OFFICE.

EDWARD THURLOW, OF ALBERT PARK, AND PERCY NORMAN I-IIGNETT, OF ST.KILDA, VICTORIA, ASSIGNORS TO GEORGE JOHN BETTS AND FREDERICK THEODOREBOWER, OF ST. KILDA, VICTORIA.

COMPOSITION FOR CLOSING PUNCTURES IN PNEUMATIC TIRES.

SPECIFICATION forming part of Letters Patent No. 609,636, dated August23, 1898. Application filed May 12,1898. Serial No. 680,491. (Nospecimens.)

To all whom it may concern.-

Be it known that we, EDWARD THURLOW, engineer, residing at No. 19 Albertroad, Albert Park, near Melbourne, and PERCY NOR- MAN I-IIGNETT,salesman, residing at No. 7 Grey street, St. Kilda, in the BritishColony of Victoria, have invented an Improved Elastic ViscousComposition Principally Useful for Automatically Closing and SealingPunctures in Pneumatic Tires, of which the following is a specification.

This invention has been devised mainly for the purpose of providingmeans for automatically closing and sealing punctures in pneumatic tiresfor bicycles, although it is obvious that it is applicable for a similarpurpose to pneumatic tires for vehicles and flexible pneumatic tubes,pads, and cushions of every description.

It consists of the following ingredients mixed in the manner andproportions substantially as set forth-that is to say, twentyfour partsof pure india-rubber are placed in a suitable vessel and sub'ected toheat until the rubber isthoropgLy neltedT WheTfthis has beenaccomplished and the melted rubber is at or about boiling-point, threeparts of French chalk are added and thoroughly mixed. This mixture isthen allowed to cool to about 180 Fahrenheit, when four parts of meal,preferably wheatmeal, are added and thoroughly mixed with it. This isthen allowed to cool to about 160 Fahrenheit, when one part of glycerinis added, and the whole thoroughly mixed together, the product being ourimproved elastic viscous composition.

It will be seen that the india-rubber is the basis of our composition.The French chalk is added for the purpose of stiffening the composition,the wheat-meal is added for the purpose of thickening it withouthardening it, and the glycerin is added for preserving its viscosity.

Instead of pure india-rubber impure may be used so long as it is notadulterated to too great an extent. If it will not sink in water,

it is sufficiently pure for the purpose of assistin g in the manufactureof our composition. If it will sink, it is not advisable to use it.

Vulcanized india-rubber might be used if it were heated until all thesulfur it contained were driven off. In any case the ber s h o l,lld bea bout the consispen cy of very thick molasses, and when the Frenchchalk is added it should be about the consistency of light dough.

As to the glycerin, the mixture must not be sufficiently cooled as toprevent the glycerin being intimately mixed with it, and in the event ofthe composition being required for use in cold countries a largerproportion of glycerin may be added, so as to prevent the compositionbecoming too hard.

Our composition may be spread by any suitable means onto the innersurface of the tube, pad, or cushion to which it is to be applied, andmay be .put on to any thickness which the operator may think desirable,and it must be covered with some suitable material to prevent itsadhering together when the two sides of the tube, pad, or cushion arecompressed together. When being used for what is known as the Fleustire, we pre fer to place it between the folds of the fabricconstituting the inner part of the tire. Its

operation is that when the tube is punctured,

say by a nail or any other article, a certain proportion of ourcomposition will remain attached to the nail, and as it is withdrawn thecomposition will automatically follow it and close and seal the orificewhich has been formed by the puncturing article.

Having now particularly described and ascertained the nature of our saidinvention and in what manner the same is to be performed, we declarethat what we claim is- The herein-described elastic viscous compositionconsisting of melted india-rubber, chalk, meal and glycerin, in aboutthe proportions and for the purpose specified.

EDWARD THURLOW. PERCY NORMAN HIGNETT.

Witnesses:

EDWARD WATERS, EDWARD WATERS, J r.

